The present application is related to and claims priority from Japanese Patent Application No. 00-101196, filed on Mar. 31, 2000.
The present invention relates to a device for recording and writing back information and method of recording and writing back for the same. More specifically, the present invention relates to a device and method for recording and playing back information where the information spans multiple recording media, recording being performed so that continuity of the information is maintained, and playback of the information being performed so that continuity of the information is maintained.
In disk changer devices being implemented as file server system devices for computer systems, high effective storage capacity is provided using multiple optical disks that can be automatically changed in a recording/playback device for optical disks. The optical disks are rewritable optical disks such as DVD-RAM (Digital Versatile Disc-Random Access Memory) or DVD-RW (Digital Versatile Disc-Rewritable). Further expected applications that take advantage of these high capacities include home server devices that can record and playback information over a long period of time, e.g., multiple broadcast programs.
For example, in the technology described in Japanese Laid-Open Patent Publication Number Hei 11-328824, fixed recording/playback means such as a hard disk device is combined and controlled together with a disk changer device that handles multiple removable recording media such as optical disks. When information is being recorded and disks are changed, information continues to be transferred. This information is stored temporarily on the hard disk device as linking information. After recording to the optical disk is completed, the linking information is recorded at the start or at the end of the information recorded on the optical disk. This allows the continuity of the recorded information to be maintained so that information can be recorded in a defect-free manner spanning multiple disks. When playing back the information, the linking information is temporarily stored in the hard disk device before playing back is begun. Then, when a disk change takes place during the playback operation, the linking information present on the hard disk device is playback so that the continuity of the information can be maintained during the playback operation without interruption.
With the growth in digital broadcasting and the increase in the number of channels available for broadcast programs, it is expected that the number of programs that a particular user may want to record will increase. Furthermore, broadcast receiver tuners have been implemented equipped with hard disk devices that are programmed to perform automatic scheduling of recording operations, allowing the recording of programs desired or frequently watched by a user. In such cases, a limitation is imposed by the recording capacity of a single hard disk device or the recording capacity of a single optical disk. If there is insufficient space available, the recorded information must be removed or the recording operation must be interrupted. Also, since the hard disk devices cannot be swapped, it would only be possible to swap the devices themselves. Thus, usage other than for the recording of temporary information should be minimized.
For these reasons, disk changers that perform recording and playback while automatically changing disks can eliminate the inconveniences associated with disk-changing. Since multiple disks can be treated as a single imaginary high-capacity recording medium, long programs can be recorded without needing to be concerned about the recording capacity left on a single optical disk. However, it is necessary to use the recording capacity in each optical disk efficiently and time continuity must be maintained for the recording and playing back of information during the changing of disks. Furthermore, search operations on the recorded programs must be efficient.
Since the user will select a program to view out of multiple recorded programs, the optical disk containing the information for the selected program will often not be inserted into recording/playback means in the disk changer device. The searching and changing of the target disk can result in a delay on the order of dozens of seconds between the selection of a program to be played and the actual playback of the recorded program. Similar problems are involved when a selected recorded program that is being played back is interrupted and a different recorded program is selected and played back. These problems decrease the ease of use of the device.
Also, when information is recorded from start to finish so that it spans multiple disks in order to make effective use of storage capacity in individual optical disks, disk changing intervals take place during which no recording is performed. Thus, the information recorded on the optical disks will be incomplete. In the conventional technology described above, information from the disk changing interval is recorded temporarily to a hard disk device as linking information, and this linking information is recorded in an assigned linking information area on the optical disk. This allows time continuity of the recorded information to be maintained while allowing information to be recorded without any gaps.
But in the conventional technology described above, if the recorded program selected for viewing spans multiple disks, linking information for the interval in which the disk changing takes place must be read and stored on the hard disk device before playback is begun. As a result, a delay of dozens of seconds is required between the selection of a recorded program to view and the actual start of playback so that the target optical disk can be changed in. Also, time to record the linking information to the hard disk device is required. These issues lead to the problems described above.
In accordance with the present invention, apparatus and method for recording on an information device includes a first data transfer component configured to store recording information on a first recording medium. There is a second data transfer component configured to store recording information on a second recording medium and to retrieve information recorded on the second recording medium. A control circuit is provided to transfer data between the first and second data transfer components. A leading section of recording information is stored on the second recording medium as leading information. Subsequent recording information is stored on the second recording medium as temporary information. The control circuit controls the second data transfer component to read out unread information first from the leading information and then from the temporary information so that continuity of recording information is maintained.
In accordance with another aspect of the invention, apparatus and method for reading from an information device includes a first data transfer component configured to retrieve recording information from a first recording medium. A second data transfer component is provided to store and subsequently retrieve recorded information on a second recording medium. A control circuit provides data transfer between the first and second data transfer components. In response to receiving a playback signal, the control circuit controls the second data transfer component to search for and read out leading information stored on the second recording medium. The control circuit detects when the first recording medium is ready for reading out data and in response thereto controls the first transfer component to read from the first recording medium associated information subsequent to the leading information. The control circuit further controls the second transfer component to record the associated information as temporary information on the second recording medium and to read out the temporary information so that continuity of playing back the recorded information is maintained.
The present invention performs recording and playback of information spanning multiple optical disks without generating gaps and minimizes the delay before playback is begun.